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  • ThesisItemOpen Access
    Management of foot rot of black pepper (Piper nigrum L.) with mycoinoculant enriched vermicompost
    (Department of Plant Pathology, College of Agriculture, Vellayani, 2002) Divya, S; Sasikumar Nair
    The study, "Management of foot rot of black pepper (Piper nigrum L.) with mycoinoculant enriched vermicompost" was done at the Department of Plant Pathology, College of Agriculture, Veliayani to explore the possibility of using vermicornpost as a carrier material for mass production of biocontrol agents and to test its efficacy in controlling the disease. The talc based inoculum of Trichoderma harzianum and soil based granular inoculum of Glomus Jasciculatum were mass produced in vermicompost either alone or in combination with farmyard manure or neem cake in the ratio 1 : 1 and 5 : 1 respectively and the efficacy was compared with the standard carrier material of FYM + neem cake (10 : 1). The population of T. harzianum 15 DAI was maximum in the treatment combination of VC + NC (5 : 1). However, the influence of these carrier materials on percentage of mycorrhizal infection 50 DAI was not statistically significant. Vermicompost as a carrier material for biocontrol agents was further tested in pepper var. Karimunda inoculated with P. capsici. Carrier materials as such had no significant influence on disease control. Reduction in foliar infection, disease index, stem infection and percentage mortality was observed in treatments with biocontrol agents. Disease control was maximum with the treatments involving T. harzianum while plant growth promotion was maximum with G. Jasciculatum. The physiological changes in pepper plants after inoculation with P. capsici and biocontrol agents were studied. The phenol and OD phenol content was more in pathogen inoculated plants. The defence related enzymes peroxidase, polyphenol oxidase and phenylalanine ammonia lyase were enhanced with pathogen inoculation as well as with the application of biocontrol agents. SDS-PAGE analysis of proteins with samples extracted from plants one day after inoculation of pathogen showed the presence of two novel proteins with molecular . weights of 78 kDa and 28 kDa in diseased samples which were absent in treatments without pathogen and also in plants treated with COC.
  • ThesisItemOpen Access
    Anthracnose disease of vegetable cowpea [Vigna unguiculata subsp. sesquipedalis (L.) verdcourt]
    (Department of Plant Pathology, College of Horticulture, Vellanikkara, 1999) Praveen Kumar, M; KAU; Sally Mathew, K
    A study on vanous aspects of anthracnose disease of cowpea was conducted at College of Horticulture, Vellanikkara during 1997-98. Etiological studies revealed Colletotrichum lindemuthianum (Sacc. and Magn.) Br. and Cav. as the main pathogen causing anthracnose disease in Kerala and the pathogen was found to be seed borne. Among the 50 genotypes tested, Kanakamony was found immune to the disease and seven genotypes were highly resistant to the disease. In ( disease management studies, all fungicides, botanicals and antagonist Trichoderma viride were equally effective under in vitro and field conditions. As far as disease control, yield and C:B ratio were concerned, mancozeb was found to be the best treatment. Summer season was found to be the best season for cowpea cultivation in areas where anthracnose is a problem. In crop loss assessment, significant difference was noticed between carbendazim treated and untreated plots in case of disease infection and yield, and yield loss of 53.85 per cent was recorded under natural condition due to this-disease.
  • ThesisItemOpen Access
    Biocontrol of rhizome rot of ginger using selected antagonists
    (Department of Plant Pathology, College of Horticulture, Vellanikkara, 1999) Julie George, K; KAU; Sukumaravarma, M
    Rhizome rot of ginger cas used by Pythium aphantdermatum (Edson) Fitzpatrick is one of the most destructive diseases of ginger in Kerala. The pathogen was isolated and its pathogenecity was established by Koch's postulates in ginger variety Rio-de-Jenerio. Among the various food bases evaluated, for the mass multiplication of selected antagonists, rice hull was found to be significantly superior to all others to obtain maximum growth for Trichoderma viride and Aspergillus flavus. For Aspergillus niger, rice bran was found to be significantly superior. The results on the effect of various treatments on germination showed that there was no significant difference among the treatments. The effect of antagonists on the pre- emergence rotting and post-emergence rotting (rhizome rot) were studied. In plots where antagonists (T viride, Aflavus or A. niger) or fungicides (mancozeb or copper oxychloride) were applied either as seed treatment or as soil incorporation at the time of planting, the pre-emergence rotting was not observed. The plot in which the antagonists T. vtride, A. mger and At flavus were applied in combination at 60 and 120 OAP, recorded the minimum rhizome rot incidence compared to other treatments. The plots in which the antagonists were applied twice, i.e., 60 and 120 OAP, the rhizome rot incidence was minimum compared to the plots with only one time application of antagonists. The maximum population of the pathogen P. aphanidermatum. was observed in plot where A. flavus was applied in combination with mancozeb. The multiplication of selected antagonists, 7: viride, A. flavus and A. niger in soil was found out by estimating their population at different stages. The population of T. virtde was maximum in plots where it was applied in combination with mancozeb in most of the period. The soil application of the combination of antagonists T. viride, A. flavus and A. niger did not affect the multiplication of anyone of them in soil. In general, soil incorporation of antagonists was found to helping in their mulitplication profusely compared to the seed treatment. The incorporation of the antagonists A. flavus and A. niger to the plots, twice was found to be superior than applying them only once, for getting maximum multiplication of propagules in soil. The result on the compatibility of antagonist with fungicide in field condition revealed that the antagonist T viride was quite compatible with mancozeb whereas A. flavus and A. niger were compatible with both fungicides tested (mancozeb and copper oxychloride). The treatments which was found to be superior in minimising the incidence of rhizome rot of ginger viz., T 16 (soil incorporation of T vir/de, A. niger at 60 and 120 DAP) and TI9 (soil incorporation of I: viride, A. niger and A. flavus) also recorded the maximum yield of ginger.
  • ThesisItemOpen Access
    Associative effect of azospirillum and bradyrhizobium on nodulation and growth of cowpea (viqna unquiculata (l.) walp,
    (Department of Plant Pathology College of Horticulture Vellanikkara, 1992) Sunitha, Menon S.; KAU; Rajendran, Pillai M .V
  • ThesisItemOpen Access
    Studies on the pathogenicity and physiology of Cornespora cassiicola (Berk & Curt.) Wei.
    (Division of plant Pathology ,Agricultural College and Research Institute ,Vellayani, Trivandrum, 1970) George, P V; KAU; Paily, P V
  • ThesisItemOpen Access
    Studies on the production of toxic metabolites by Trichoconis padwickii ganguly in culture filtrate
    (Division of plant Pathology ,Agricultural College and Research Institute ,Vellayani, Trivandrum, 1969) Jayachandran Nair, K; KAU; Sam Raj, J
  • ThesisItemOpen Access
    Effects of collar mot and ring-barking on the Rhizosphere microflora and certain chemical constituents of sword bean plants
    (Division of plant Pathology ,Agricultural College and Research Institute ,Vellayani, Trivandrum, 1968) Kanakambaran, P N; KAU; Sam Raj, J
  • ThesisItemOpen Access
    Air spora over rice crop with special reference to Piricularia oryzae Cav.
    (Division of plant Pathology ,Agricultural College and Research Institute ,Vellayani, Trivandrum, 1967) Maheswari Amma, S; KAU; Sam Raj, J
  • ThesisItemOpen Access
    Mosaic disease of Dolichos bifforus L., transmission , host range and effect of the virus on the host
    (Division of plant Pathology ,Agricultural College and Research Institute ,Vellayani, Trivandrum, 1967) Sukumara Dev, V P; KAU; Sam Raj, J